A radiation hybrid map of the human genome

We have developed a panel of whole-genome radiation hybrids by fusing irradiated diploid human fibroblasts with recipient hamster cells. This panel of 168 cell lines has been typed with microsatellite markers of known genetic location. Of 711 AFM genetic markers 404 were selected to construct a robust framework map that spans all the autosomes and the X chromosome. To demonstrate the utility of the panel, 374 expressed sequence tags (ESTs) previously assigned to chromosomes 1, 2, 14 and 16 were localized on this map. All of these ESTs could be positioned by pairwise linkage to one of the framework markers with a LOD score of greater than 8. The whole genome radiation hybrid panel described here has been used as the starting material for the Genebridge4 panel that is being made widely available for genome mapping projects.      

Hypoplastic left heart syndrome: report of an operation utilizing the ductus arteriosis in outflow reconstruction

An operation utilizing the ductus arteriosus to construct an outflow tract from the right ventricle is described. This operation uses the right ventricle for pulsatile flow to both systemic and pulmonary arteries, provides complete reconstruction of the ascending aorta and arch, and delivers predictable pulmonary blood flow. Although unsuccessful in this case report, which involves a hypoplastic left heart syndrome patient, the technique may provide successful palliation with the use of ductal tissue. This method has not been previously described.     

Sodium-lithium countertransport and family history of hypertension in childhood

We have studied the relationship between sodium-lithium countertransport, determined in childhood, and family history of hypertension. Countertransport was measured in healthy children and those with secondary hypertension. There was no significant difference in countertransport between these two groups. In the normal children ( n = 52, median age 6.8 years), there was a positive relationship between body mass index and countertransport (r_s= 0.34, p <0.02). A positive relationship between family history of hypertension using a ranked scoring system, and countertransport, not related to age, body mass or blood pressure (n = 34, r_s= 0.63, p<0.001 ) was also found. There was no significant relationship between intraccllular sodium concentration and countertransport. These data confirm that countertransport in normal children is related to body mass index and indicate that a genetic predisposition to primary hypertension marked by sodium-lithium countertransport is identifiable in childhood.     

Comparison of prosthetic graft materials as intracardiac right atrial patches

An experimental animal model was developed to study the fate of prosthetic graft materials within the heart. Autologous pericardium, bovine pericardium, polytetrafluoroethylene, woven Dacron, and autologous right atrium (control) patches were implanted into the wall at three sites on the right atrium in each of 10 dogs (six patches for each graft material). The atria were harvested 90-100 days later and histologic examination and quantitation of calcium were performed. Chronic inflammation and fibrosis were found in 29 of 30 grafts. Cartilage formed in 26 of 30 sites and was found both in the center and around the edges of the grafts. In addition to cartilage, bone including marrow elements formed in the two autologous materials at 4 of the 12 sites and in 1 of the Dacron graft sites. Calcium content was greater in the control and the bovine pericardial grafts than in the other graft materials (P = NS). The incidence and degree of inflammation, fibrosis, calcification and cartilage, and bone formation were similar in all materials. We conclude that the healing process of these intracardiac graft materials is a generalized phenomenon independent of the inherent properties of a specific graft material.     

Planning for children whose parents are dying of HIV/AIDS. American Academy of Pediatrics. Committee on Pediatric AIDS, 1998-1999

Although the character of acquired immunodeficiency syndrome is changing into a chronic illness, it is estimated that by the end of this century, 80 000 children and adolescents in the United States will be orphaned by parental death caused by human immunodeficiency virus infection. Plans for these children need to be made to ensure not only a stable, consistent environment that provides love and nurturing, but also the medical and social interventions necessary to cope with the tragic loss. Pediatricians should become aware of local laws and community resources and initiate discussion early in the course of parental illness to facilitate planning for the future care and custody of the children. States need to adopt laws and regulations that provide flexible approaches to guardianship and placement of children orphaned by acquired immunodeficiency syndrome.     

Computed tomography for cervical spine trauma. The impact of MDCT on fracture detection and dose deposition

A multidetector computed tomography (MDCT) was installed in our department. Referral rates, examination protocols and detection rates of abnormal findings in CT examinations for cervical spine trauma 6 months before and 6 months after MDCT installation were compared to look for changes in practice. Retrospective analysis of all CT cervical spine examinations in patients with multiple trauma over two contiguous 6-month periods: from July 2003 to December 2003 (helical CT) and from January 2004 to June 2004 (MDCT). Variables recorded were number of CT examinations performed, scan plane coverage and traumatic abnormalities detected. Phantom dosimetry measurements for cervical spine examination in both helical CT and MDCT were compared. One hundred and fifty four patients underwent cervical spine CT during these periods. Helical CT period: of 91 patients undergoing CT cervical spine examination for trauma, 65 (71%) were complete cervical examinations and 26 (29%) were level-specific examinations. Eight patients (9%) had cervical spine fracture, six of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 24.76, 1.86 and 0.21 mGy, respectively, for complete cervical spine examinations. MDCT period: of 63 patients who underwent CT cervical spine examination for trauma, 61 (97%) were complete examinations and 2 (3%) were level-specific examinations. Six patients (11%) had cervical spine fracture, three of which were apparent on radiographs. Dose estimations for thyroid, lens and breast were 75.8, 9.7 and 0.7 mGy, respectively, for complete cervical spine examinations, which were notably higher than those for helical CT. After installation of MDCT, clinical requests for complete examination of the cervical spine following trauma increased. This changing trend resulted in a significantly higher radiation dose to thyroid, lens and breast.     

Livestock-associated Methicillin-Resistant Staphylococcus aureus Sequence Type 398 in Humans, Canada

Rates of colonization with livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) sequence type 398 have been high for pigs and pig farmers in Canada, but prevalence rates for the general human population are unknown. In this study, 5 LA-MRSA isolates, 4 of which were obtained from skin and soft tissue infections, were identified from 3,687 tested MRSA isolates from persons in Manitoba and Saskatchewan, Canada. Further molecular characterization determined that these isolates all contained staphylococcal cassette chromosome (SCC) mecV, were negative for Panton-Valentine leukocidin, and were closely related by macrorestriction analysis with the restriction enzyme Cfr91. The complete DNA sequence of the SCCmec region from the isolate showed a novel subtype of SCCmecV harboring clustered regularly interspaced short palindromic repeats and associated genes. Although prevalence of livestock-associated MRSA seems to be low for the general population in Canada, recent emergence of infections resulting from this strain is of public health concern.     

Current use of myocardial protection during coronary artery bypass surgery: results of a survey

The literature suggests that certain methods of myocardial protection employed during coronary artery bypass graft (CABG) surgery may significantly affect postoperative recovery. A retrospective study comparing the use of different cardioplegia solutions during CABG surgery at our institution failed to show significant differences in perioperative ischemic events or in patient survival. A subsequent survey was conducted among 140 surgeons worldwide to determine the influence of myocardial protection on perioperative ischemic events and patient survival.